1. Field of the Invention
This invention relates to tire curing presses, and especially presses generally referred to as the slide-back type wherein the upper sidewall mold is raised upwardly and then carried horizontally away from the axis of the lower sidewall mold to facilitate loading of a new uncured tire carcass and removal of the cured tire. More particularly, the invention relates to a center mechanism for a tire press of the type described, that is used to perform several functions during the molding process including the opening and closing of a segmented tread mold assembly, the removal of the deflated forming bladder from the tire carcass and the operation of a chuck used to strip a cured tire from the lower sidewall mold and eject it from the upper sidewall mold when it is displaced laterally from the mold axis.
2. Description of the Prior Art
In automatic tire presses, such as those used in the manufacture of radial cord tires, a torroidal uncured tire carcass is loaded in a bottom mold section when the press is open and the top mold section then closes on top, while at the same time, a segmented tread mold assembly is moved to a closed position to provide the tread forming portion of the mold. Then a forming bag or bladder is inflated within the carcass prior to the closing the press to assist in shaping the tire during the curing process.
In automatic tire presses generally referred to as slide-back presses, the top mold section moves directly upward after the curing operation and then laterally away from the bottom mold section. This positions the shaped tire at a location where it may be stripped from the top mold section and dropped on a conveyor, or the like.
In this type of press, it is necessary that certain operating equipment be carried on the movable beam that carries the upper mold section, or as is usually the case, a pair of upper mold sections. These mechanisms must accomplish several functions to include operating the segmented tread forming mold sections, forcing the forming bladder, once the cure is accomplished, out of the interior of the cured tire and into a retainer well generally located in the middle of the lower sidewall forming mold section, and operating a clutch mechanism that expands into a position where it may engage the tire beads to retain the tire in the upper mold section during its removal from the lower mold section.
In the past, a ram/ejector mechanism has been located centrally and has been adapted for reciprocating vertical movement along the central axis of the mold cavity. However, the mechanism for operating the segmented mold sections has included a plurality of fluid cylinders spaced radially outwardly from the ram/ejector mechanism. This has caused certain problems. In particular, it is difficult to synchronize two or more fluid cylinders that support the segmented mold operating mechanism and uneven pressures can often cause binding and subsequent malfunction.
The center mechanism of the present invention, however, enables all of these operating functions to be achieved utilizing elements which have guided movement through tubular members located concentrically about the axis of the molding cavity.